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Biomedical subjects

A Rubino

Publications and source records attributed to A Rubino.

At least 91 records · Page 5Linked to original sources
PubMed1990

[Mitral valve replacement in young children: a long-term follow-up].

The Authors report follow-up data (mean 60, range 13-101 months) from 4 patients under two years of age (mean 11.5 months) operated on for prosthetic mitral valve implantation. Two patients were male and two female. Pre-operative diagnosis was partial atrioventricular septal defect with parachute mitral valve in one case and isolated mitral valve anomaly in the others (1 parachute, 2 hammock valves). One bioprosthesis (Liotta n. 23) and three mechanical prostheses (Björk-Shiley) were implanted. Complications occurred in two patients: one case of endocarditis on the bioprosthesis, leading to substitution with a Björk-Shiley valve; one case of acute thrombosis 8 months after implantation in the only pt receiving aspirin as prophylactic therapy. This complication was resolved by intravenous thrombolytic agents. All the patients are alive, in I NYHA functional class and receiving oral anti-coagulants. Instrumental follow-up with eco-Doppler demonstrated normal functioning prostheses in all the patients. A sub-aortic gradient was found in the patient with partial atrioventricular septal defect. Prosthesis-patient mismatch was identified in a patient operated on when she was 6 months old who was followed-up for 5 years.

Bioprosthesis↗
PubMed1989

Characteristics and mechanism of action of a heat-stable enterotoxin produced by Klebsiella pneumoniae from infants with secretory diarrhea.

Escherichia coli heat-stable enterotoxins (ST) are classified into STa and STb according to their physicochemical and biologic characteristics. STa induces diarrhea, activating the guanylate cyclase-cGMP system. ST-like enterotoxins can be produced by bacteria other than E. coli, including Klebsiella pneumoniae. A Klebsiella ST has previously been shown to share some chemical and immunologic characteristics with E. coli ST. Aiming to define better the nature of Klebsiella ST, we have screened 237 children with diarrhea and 179 controls for ST-producing Klebsiella, using the SMA. We detected 26 Klebsiella strains from patients, two of which were positive in the SMA, and 36 from controls, all negative for ST. A partial purification was performed using an acetone precipitation followed by ultrafiltration and gel filtration techniques. Klebsiella toxin was heat-stable, methanol-soluble, sensitive to mercaptoethanol, active at acid pH values, but not at pH greater than 8. The time course of Klebsiella toxin in the SMA resembled that of E. coli STa. Klebsiella ST caused reduced Na absorption and net Cl secretion in rabbit ileal mucosa mounted in Ussing chambers. It was found to increase the cGMP but not the cAMP concentration. Finally, Klebsiella ST did not react with anti-E. coli STa MAb in a competitive ELISA. We conclude that K. pneumoniae may induce diarrhea through the production of an STa similar but not identical to E. coli STa.

Bacterial Toxins↗
PubMed1989

[Short-term antibiotic prophylaxis with ceftriaxone in general surgery].

The authors report their own experience on the efficacy of a short term antimicrobial prophylaxis involving a long-acting cephalosporin, ceftriaxone (Rocefin), in surgical patients. A study was carried out to evaluate the efficacy of a single dose of 1 or 2 g by i.v. administered 1 h. before elective surgery. 100 patients were admitted to study. Therapeutic success was achieved in 92 cases (92%).

Adolescent↗
PubMed1989

[Pulmonary arteriovenous aneurysm coexisting with rheumatic mitral valvulopathy in Rendu-Osler-Weber syndrome. Image diagnosis using bidimensional and Doppler echocardiography].

The authors report a case of the rare association described in the title in which echocardiography played an important role in the recognition of the pulmonary arteriovenous aneurysm. By 2-D approach it was possible to visualize a wide anechogenic concamerated area containing an echodense mass and continuous with the left heart cavities. Pulsed Doppler interrogation at the level of the extra-cardiac cavity showed a flow signal which gave the first diagnostic evidence of a vascular lesion. Direct visualization of pulmonary arteriovenous aneurysms has never before been obtained with echocardiography. This was possible in the present case due to contiguity with heart chambers and the large dimension of the aneurysm. Doppler examination gave the first confirmation of the vascular nature of the lesion. Angiography is still a mandatory pre-operative procedure but 2-D and Doppler echocardiography may play an interesting role in the diagnostic non invasive procedure of pulmonary arteriovenous aneurysms.

Arteriovenous Fistula↗
PubMed1988

Unconjugated bilirubin and the bile from light exposed Gunn rats inhibit intestinal water and electrolyte absorption.

Jaundiced babies undergoing phototherapy often develop diarrhoea. The cause of it is still uncertain. Increasing evidence supports a role of a secretory mechanism for the diarrhoea. We therefore studied the effects of bile from congenitally jaundiced rats undergoing phototherapy and of unconjugated bilirubin on rat small intestine in vivo and in vitro. Results suggest that: (1) the bile from homozygous Gunn rats under phototherapy has an anti-absorptive effect when tested in the perfused jejunum of normal Wistar rats; (2) unconjugated bilirubin has a dose dependent secretory effect on the intestinal transport of water and electrolytes, when tested in the same system. Alteration of cyclic AMP or cyclic GMP, known intracellular mediators of secretion, was not observed. We conclude that free bilirubin is an intestinal secretagogue acting by an as yet unknown mechanism, that may mediate the secretory type of diarrhoea in jaundiced neonates undergoing phototherapy.

Animals↗
PubMed1988

Myocardial function in heart failure.

Overt cardiac failure usually presents with constant clinical features as consequences of the reduced pump action, associated with an increased adrenergic drive, independent of the underlying disease. However, the study of left ventricular function, before and during the phase of cardiac insufficiency, shows that different pathophysiological mechanisms are responsible for the symptoms and signs of reduced cardiac action. It is possible to recognize that cardiac failure is caused primarily by: (1) early severe depression of the inotropic state, i.e. dilated cardiomyopathies; (2) late inadequate level of ventricular hypertrophy, with normal contractility, i.e. aortic stenosis; (3) early inadequate level of hypertrophy and slightly reduced inotropic state, i.e. mitral insufficiency, and (4) late inadequate level of hypertrophy and severe progressive reduction in contractility, i.e. aortic insufficiency. The possibility of an 'in vivo' assessment of the different determinant parameters of left ventricular function (contractility, afterload, preload, fiber and chamber compliance) through echocardiography enables a better understanding of the mechanisms leading to the cardiac failure and a more efficient therapeutic approach.

Echocardiography, Doppler↗
PubMed1987

Rhein: an anthraquinone that modulates superoxide anion production from human neutrophils.

Rhein (4,5-dihydroxyanthraquinone-2-carboxylic acid), the active metabolite of diacetylrhein, which has been reported as an effective antirheumatic drug in man, inhibited superoxide anion production from human neutrophils challenged with N-formylmethionyl-leucyl-phenylalanine (FMLP: IC50, 2 x 10(-5) M) and A23186 (IC50, 10(-5) M), but not with phorbol myristate acetate. In the same concentration range (10(-6)-10(-3) M), the drug did not affect oxy-radical production by a cell-free hypoxanthine-xanthine oxidase system and exerted weak inhibitory effects on FMLP-evoked lysosomal enzyme release. Rhein inhibitory effects on neutrophil functioning may contribute to the overall therapeutic activity of the parent drug, diacetylrhein.

Adult↗
PubMed1987

Production of Escherichia coli STa-like heat-stable enterotoxin by Citrobacter freundii isolated from humans.

Citrobacter species are often present in the stools of children and are generally considered a normal component of the intestinal microflora. Previous reports suggested that they might act as enteric pathogens. Aiming at defining the role of Citrobacter species in inducing diarrhea, we looked for their presence in the stools of 328 children with diarrhea and in 108 controls. Citrobacter strains were isolated from 46 patients (14%) and 7 controls (6.5%) (P less than 0.05). All isolates were tested for heat-stable (ST) and heat-labile (LT) enterotoxin. No LT-producing organisms were found. Three C. freundii strains, all isolated from children with diarrhea, elaborated an enterotoxin detected by the suckling mouse assay. A crude extract was prepared by acetone precipitation and a sequential ultrafiltration technique. The enterotoxin was heat stable, and its estimated molecular weight was between 2,000 and 10,000. Citrobacter enterotoxin was soluble in methanol and stable at acid and neutral pHs but not above pH 8, and its activity was destroyed by treatment with 2-mercaptoethanol. Citrobacter enterotoxin was inactive in the 18-h rabbit ileal loop test. All these characteristics closely resemble STa produced by Escherichia coli. The time course of Citrobacter enterotoxin-induced intestinal secretion in suckling mice was similar to that of E. coli STa. The enterotoxin produced by C. freundii cross-reacted with monoclonal antibodies raised against E. coli STa. These results suggest that C. freundii is capable of inducing diarrhea through the production of an E. coli-like STa, and its presence in the stools of patients with diarrhea should be considered as that of a possible etiologic agent.

Bacterial Toxins↗
PubMed1987

[Angiocardiography with axial projections in the study of various types of intraventricular septal defects].

The exact site of an interventricular septal defect (VSD) is important mainly to program surgical treatment. The present study takes into consideration the possibility of the axial angiocardiographic method to identify the site of the interventricular septal defect. With this goal 126 cases of VSD in infancy were retrospectively studied with left ventriculograms using angled "long-axial" and "four chambers" views. In 62 cases the anatomic-angiographic correlation of the VSD site was reached, and was confirmed at surgery. The most frequent localization of the VSD was perimembranous (89 cases, 70%). The rarest localizations were the sub-arterial and the multiple VSD. The personal experience agrees with the data found in literature, namely that angiocardiography performed with axial views has an elevated diagnostic reliability in the various types of VSD.

Angiocardiography↗
PubMed1987

[Atresia of the tricuspid valve and total anomalous supracardiac pulmonary venous return. Description of a case associated with severe extracardiac malformations].

The Authors report a case of tricuspid atresia and total anomalous pulmonary venous return of the supracardiac type, with mild pulmonary valve stenosis and extracardiac malformations as anal atresia, microphthalmia and irideo and chorioretinic coloboma. The Authors stress the importance of the electrocardiogram and standard chest X-Ray to "suspect" this rare association.

Abnormalities, Multiple↗
PubMed1986

FMLP-activated neutrophils evoke histamine release from mast cells.

Human neutrophils, having been activated by the chemotactic peptide N-formylmethionyl-leucyl-phenylalanine (FMLP), evoke histamine release from rat serosal mast cells. The release is dependent on FMLP concentration and it can be inhibited by disodium cromoglycate and by a flavonoid, silymarin, which displays free radical scavenging properties. Silymarin inhibition of neutrophil-mediated histamine release is dose-dependent. These results further stress the concept of a neutrophil-mast cell interaction, which may be involved in inflammatory processes.

Adult↗
PubMed1985

Acute childhood diarrhoea in Naples: an aetiologic study.

A potential aetiologic agent was detected in the stools of 56% of 118 children hospitalized in Naples for acute diarrhoea. Rotavirus and Salmonella were the agents most commonly associated with disease, accounting for 23 and 17 percent of cases, respectively. Campylobacter jejuni, enterotoxigenic Escherichia coli, Yersinia and Shigella were less frequently isolated (total, 11% of cases). These findings fit well with the epidemiological picture described for other developed countries, except for the isolation rate of Salmonella which widely exceeds that reported in other investigations. Cytotoxic strains of E. coli and other Gram-negative bacilli were identified in the stools of 18 children; the possible pathogenic role of these strains is unknown and needs further investigation.

Acute Disease↗